The team, which was also working with scientists from Argentina, found two fossils believed to be from some of the oldest land-living mammals in the world, during a mission to Seymour Island off the Antarctic Peninsula.
One fossil (pictured above) is a 2.5 cm foot bone thought to belong to “a very heavy mammal”, Thomas Mörs, a paleontologist at the Sweden’s Natural History Museum told The Local.
But he said that scientists were unsure exactly which creature it was from.
The other fossil is a section of a tooth belonging to an “animal with hooves”, he added.
Researchers believe the animals lived on the ice-covered continent between 65 and 35 million years ago, when the climate was much warmer than it is today.
“This exciting discovery pushes forward our knowledge about the previous inhabitants of the Antarctic,” said Mörs.
Mörs added that the discovery has also caused scientists to question at what date mammals spread from South America to Antarctica, which used to be connected.
The findings were made in August and published in the journal Paleontology, although the Natural History Museum, which helped to fund the project, only released details on Tuesday.